Armchair



FIG. 1 is a front left perspective view of an armchair according to thedesign;

FIG. 2 is a back right perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof; and,

FIG. 5 is a side view thereof, the opposite side being the mirror imagethereof.

CLAIM The ornamental design for an armchair, as shown and described.